DESCRIPTION: A symposium is proposed to be held September 25-28, 1997 for the purpose of discussing the molecular mechanisms of action and the involvement of epidermal growth factor receptor (EGFR), its related genes ErbB2, ErbB3 and ErbB4, and their ligands, in development and disease. Recent findings have brought this "old" receptor gene back into prominence, not only in non-vertebrate, but also in mammalian developmental studies. The crosstalk between the EGFR and its related receptor proteins implies very complex systems of signaling and multiple choices of cellular responses. This symposium is a plan to gather together many of the major contributors to this field and to discuss the mechanisms and interactions of gene products that may be acting in homologous fashion in different species, with distinctive results. The invited speakers will present lectures 45 minutes in length with 15 minutes for discussion. Other participants will make 15 minute oral presentations of their work (with 5 minutes for discussion) or will present in a poster session. The decision of who presents orally will be the decision of the organizing committee. Frequent breaks and other opportunities for discussion are planned. The results of evaluations from the past seven symposia of this series (six of which were organized by the applicant) show that the majority of the previous participants have rated the opportunities for discussion and the intellectual stimuli from these symposia as excellent. The number of participants is relatively small (120-150) and this fosters ready interactions in a friendly atmosphere. The plenary speakers have been chosen to represent a broad range of scientific fields including biochemistry, molecular biology, developmental biology, and cancer biology. An important aspect of this symposium is that it will bring together investigators who are studying homologous signaling mechanisms in widely differing organisms, to promote new exchanges of ideas. Another important aspect is the prominence of these growth-regulating genes to human cancers and the participants who might interact to broaden their findings into potentially useful clinical applications.